Re: Best source for Servo's ?? speeds and plasma

> When moving a servo is always behind the commanded position while
> accelerating or ahead while decelerating. I have no way of

measuring the

> error but I doubt if it is more than .001" at low speed. While
> accelerating hard near rapid speed (somewhere around 200IPM if I

run

> Mach2 flat out) the error is a lot more than that, possibly as high

as

> .012". The drives will fault if the error exceeds .016" (128 steps)
>
> In practise I have turned Mach2 down to about 100IPM. 200 is bad

for my

> heart!
>
> Les

<snip>

This brings into question the use of high speeds and plasma
machines. As I understand, plasma cutters on thin stock should
operate at higher speeds.

I am getting ready to order a similar motor in this thread, but from
Surplus Center
http://www.surpluscenter.com/item.asp?
UID=2005010323083678&catname=&qty=1&item=10-1783

Items 10-1783 and 10-1573 are the motors
and item 10-1834 is a small motor with a 200 encoder.
lose the motor and use the encoder.

I am looking at the gear reduction.

It seems that XL belts might be too small, but I have not tested that
as yet.

I found a 24:60 primary ratio and a 24:60 secondary ratio into a gear
rack of 12 pitch and a 16 tooth drive gear offer 0.24 inchs per
revolution of motor.

What I have not figured is the shaft thicknesses. I hate to think it
would depend on a 1/4 shaft for the gear or some sillyness.

Here is a picture that Graham sent me (thanks Graham) of a similar
drive train. That wide drive belt seems to be hard to find and darn
expensive !

http://www.axxustech.com/Axxus4x8/Axxus%204x8%20motors.jpg

Dave